api docs: Finished adding all C-S APIs. Added initialSync, publicRooms, membership changes (generic and RPCy) and directory paths.

docs/client-server/swagger_matrix/api-docs

@@ -25,6 +25,10 @@
     {
       "path": "/events",
       "description": "Event operations"
+    },
+    {
+      "path": "/directory",
+      "description": "Directory operations"
     }
   ],
   "authorizations": {